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Beyond the measurement of $R_\ell$ at the Z pole, another interesting possibility for the $\alpha_{\rm s}$ determination is to use the W hadronic width as measured from W-pair events at and above 161 GeV. The quantity of interest is the branching ratio $B_{\rm had}= \Gamma_{\rm W \to hadrons}/\Gamma^{\rm tot}_{\rm W}$, which can extract be extracted by measuring the fractions of WW events to the fully leptonic, semi-leptonic and fully hadronic final states:   \begin{equation} \begin{eqnarray}  {\rm BR}({\rm W^+W^-} \to \ell^+ \nu \ell’^- \bar{\nu}) &  = &  (1-B_{\rm had})^2   \end{equation}   \begin{equation} had})^2,\\  {\rm BR}({\rm W^+W^-} \to \ell^+ \nu {\rm q\bar{q}’}) &  = &  (1-B_{\rm had})\times B_{\rm had}   \end{equation}   \begin{equation} had},\\  {\rm BR}({\rm W^+W^-} \to {\rm q\bar{q}' q’’\bar{q}’’’})= q’’\bar{q}’’’}) & = &  B_{\rm had}^2   \end{equation} had}^2. \\   \end{eqnarray}  The LEP2 data taken at centre-of-mass energies ranging from 183 to 209 GeV led to $B_{\rm had} = 67.41 \pm 0.27$~\cite{1302.3415}, a measurement with a 0.4\% relative precision. This measurement was limited by WW event statistics of about $4 × 10^4$ events. With over $2 \times 10^8 W$ pairs expected at TLEP at $\sqrt{s} =$ 161, 240 and 350~GeV, it may therefore be possible to reduce the relative uncertainty on $B_{\rm had}$ by a factor $\sim 70$ down to $5\times 10^{-5}$, and thus the absolute uncertainty on $\alpha_{\rm s}$ to $\pm 0.00015$.